She once worked for a fast food chicken chain, and was a little-known runner-up in a US beauty pageant before she took the Miss Alabama crown last year.

So why did Katherine Webb, a part-time model, suddenly go from having a few hundred Twitter followers to more than 170,000 in a matter of hours?

The 23-year-old model has suddenly become America's new favourite 'WAG', stealing the spotlight from her quarterback boyfriend at the Alabama-Notre Dame BCS Championship game in Miami, Florida, college football's version of the Superbowl.

While AJ McCarron was starring on the field - throwing four touchdown passes in Alabama's 42-14 victory over Notre Dame in a game watched by 26 million Americans - talk afterwards seemed largely focused on his girlfriend.

And not just after the game, either.

During the game Webb caught the attention of 73-year-old commentator Brent Musburger as ESPN cameras focused in on her sitting in the stands.

"Wow, I'm telling you quarterbacks: You get all the good-looking women," Musburger said as the camera focused on Webb, sitting with McCarron's mother.

"What a beautiful woman. Wow!"

He also recommended that Alabama boys start "playing catch in the backyard" to win a woman like Webb.

Another tweeted to ESPN: "Get Brent Musburger and his sexist comments off of TV."

On Tuesday (local time), ESPN released this statement: "We always try to capture interesting storylines and the relationship between an Auburn grad who is Miss Alabama and the current Alabama quarterback certainly met that test.

"However, we apologise that the commentary in this instance went too far and Brent understands that."

Webb, who studied a bachelor of science in business management and administration at the rival university to McCarron, told The Associated Press on Tuesday that Musburger's comments didn't bother her.

"It was kind of nice," she said. "I didn't look at it as creepy at all. For a woman to be called beautiful, I don't see how that's an issue."

Webb said her iPhone was dead during the game, but several friends showed her what was happening on Twitter and pointed out that pictures of her were being shown on TV.

"I just couldn't believe it," she said. "I was just in complete surprise."

Donald Trump was quick to jump on the bandwagon with a job offer: "We are going to ask Katherine Webb to be a judge at the Miss USA pageant coming up in Las Vegas," he tweeted.

Dee Dee Bonner, McCarron's mother, said the two laughed in the stands as Webb's Twitter count grew.

Webb earlier told the Columbus Ledger-Enquirer that she first encountered McCarron on Twitter, and they met in early December when he attended the Miss Alabama USA pageant in Montgomery.

The two visited over the holidays and publicly confirmed their romance right before the New Year.

Webb's pageant biography says she was born in Montgomery and grew up in Phenix City. Webb worked for Chick-fil-A as a training director in Columbus, Georgia, before moving to Los Angeles to pursue modelling.

She finished in the top 10 in the national pageant and top 15 in the Miss Georgia pageant in 2008.

Bonner said Webb was considering moving back to Alabama to be with the quarterback.

Before Monday's game, Webb tweeted a photo of herself wearing a jersey with McCarron's number, her arms wrapped around the quarterback.

Early Tuesday, Webb posted her first tweet to her new followers: "So extremely blessed... @10AJMcCarron. Congrats to Alabama and making history! #BCSChamps."

Webb called the experience fun and said she doesn't think McCarron minds the attention on her.

But when Arizona Cardinals defensive end Darnell Dockett tweeted Webb his telephone number and suggested they meet after the game, McCarron responded, telling Dockett, "#betterkeepdreaming like the rest of these dudes."

The game didn't just change Webb's life, but the career of Australian player Jesse Williams, who booked himself a multimillion-dollar NFL contract.

Williams is expected to be snapped up by the Pittsburgh Steelers or Indianapolis Colts in the first round of the NFL draft in New York on April 25.

Williams, born on Thursday Island and raised in Brisbane, played basketball and rugby before trying American football as a 14-year-old with Brisbane's Bayside Ravens.